154 SCIENCE PROGRESS 



nitric acid (sic). This error is due to the source from which the diagram is 

 taken ; it is a pity that a more reHable authority was not consulted. 



No mention appears to be made of the well-known Lodge-Evans process 

 for applying sulphur dyes to woollen goods. A useful feature is the inclusion 

 at the end of each chapter of a list of the more important dyes of the class 

 dealt with on the preceding pages, and the bibliography on the pages 733 to 

 750 should prove of value. In addition to the usual index there is also a 

 special index of experiments which should be useful. 



Unfortunately, owing to the confusion of names in the dye world, the 

 author has decided for the present to keep to the old German names ; but 

 there would appear to be no reasons why some of the more important names 

 of dyes given by British and American makers should not be included as 

 well ; German dyes get more than enough free advertisement as it is. 



Dr. Matthews is to be congratulated on having completed a very useful 

 and painstaking work, which will without doubt become a standard on the 

 subject it deals with, 



F. A. Mason. 



The Volatile Oils. Vol.11. By E. Gildemeister and Fr. Hoffmann. Second 

 Edition, by E. Gildemeister. Authorised translation by Edward 

 Kremers. [Pp. XX + 686, with 4 maps, 3 tables, and numerous 

 illustrations.] (London : Longmans, Green & Co.; printed 1916, 

 published 1920. Price 32s. net.) 



This volume, the authorised English translation of the second volume of the 

 second German edition of Gildemeister and Hoffmann's classical work, deals 

 with a number of the individual essential oils. The same plan has been 

 adopted as in the first edition, but the information available has grown so 

 greatly that it will require a third volume to complete the work. 



The nature and value of this book are so well known that it hardly calls 

 for much detailed review. In common with all books of this type, however, 

 it lags some years behind the times, and it is becoming more and more 

 urgent for a system to be devised for the publication of works of reference, 

 which will enable them to be kept up to date year by year. A method which 

 will not be too costly is difficult to find, but it seems desirable that some 

 international body should take up the whole question of the production of 

 standard works of reference. 



The present work has been printed by Schimmel & Co., under whose 

 auspices it was compiled, and its excellent get-up is in marked contrast to 

 the poor work being put into many similar books in this country. The 

 phraseology of the book is a worrying feature to the English reader, as it 

 reflects too closely the construction of the original German. The subject, 

 however, is dealt with in the thorough way which one would expect, and the 

 book should be in the reference library of all those interested in this branch 

 of chemical technology. 



O. L. B. 



Organic Medicinal Chemicals (Synthetic and Natural). By M. Barrow- 

 CLiFFE, M.B.E., F.I.C., and Francis H. Carr, C.B.E., F.I.C. [Pp. 

 xiv -t- 331, with 25 figures in the text]. (London : Bailliere, Tindall 

 & Cox, 1920. Price 155. net.) 



This volume is one of the series of Industrial Chemistry under the general 

 editorship of Dr. S. Rideal. A novel and refreshing feature of the work is that it 

 deals not only with the synthetic products turned out by the large chemical 

 works, but also with the preparation and properties of the large number of 

 natural products, both of plant and animal origin, which are largely used in 



